NAICS 517121: Telecommunications Resellers
This U.S. industry comprises establishments engaged in purchasing access and network capacity from owners and operators of telecommunications networks and reselling wired and wireless telecommunications services to businesses and households (except satellite telecommunications and agents for wireless telecommunications services).  Establishments in this industry resell telecommunications; they do not operate transmission facilities and infrastructure.

Illustrative Examples:

Mobile virtual network operators (MVNOs) (except agents)
Pre-paid calling cards, telecommunications resellers
Wired telecommunications resellers
Wireless telecommunications resellers (except satellite telecommunications and agents) 

ExioML sector: Post and telecommunication services (64)
Region: US | Year: 2022
Sector value added: 1318185.34972 M EUR | Employment: 6912.63288208 thousand persons
Sector GHG emissions: 14755932297.8 kg CO2 eq | Energy carrier net total: 266659.908906 TJ | Carbon intensity: 0.011194125546103478

Company: MCI Communications Corporation
MCI Communications Corp. was an American telecommunications company that was instrumental in legal and regulatory changes that led to the breakup of the AT&T monopoly of American telephony and ushered in the competitive long-distance telephone industry.